... characteristics in administrative data for a number of rheumatology conditions including diagnoses for RA, spondyloarthropathies, systemic lupus erythematosus, fibromyalgia, osteoarthritis, joint injection, ... activity measures such as the DAS28 may not adequately capture underlying RA disease activity for some patients (e.g. those with concomitant fibromyalgia). Moreover, patients may fear that they ... Johnson D: Validation of ICD-9-CM to Identify GI Perforation in Administrative Claims Data Among Rheumatoid Arthritis Patients. In: International Society of Pharmacoepidemiology: 2010; Brighton,...